Cleaning process and composition using fluorocompounds

ABSTRACT

A process for removing contaminants from the surface of a substrate comprises contacting the substrate with a cleaning composition comprising at least one mono-, di-, or trialkoxy-substituted perfluoroalkane, perfluorocycloalkane, perfluorocycloalkyl-containing perfluoroalkane, or perfluorocycloalkylene-containing perfluoroalkane compound, the compound optionally containing additional catenary heteroatoms. The compounds exhibit good solvency properties while being environmentally acceptable.

[0001] This application is a continuation-in-part of application Ser.No. 08/573,416 filed Dec. 15, 1995.

FIELD OF THE INVENTION

[0002] This invention relates to cleaning compositions comprising atleast one partially-fluorinated ether compound and to processes forremoving contaminants from substrate surfaces using such compositions.In another aspect, this invention relates to certain novelpartially-fluorinated ether compounds. In yet another aspect, thisinvention relates to coating compositions comprising at least onepartially-fluorinated ether compound and to processes for depositingcoatings on substrate surfaces using such compositions.

BACKGROUND OF THE INVENTION

[0003] Solvent cleaning applications where contaminated articles areimmersed in (or washed with) solvent liquids and/or vapors arewell-known. Applications involving one or more stages of immersion,rinsing, and/or drying are common. Solvents can be used at ambienttemperature (often, accompanied by ultrasonic agitation) or at elevatedtemperatures up to the boiling point of the solvent.

[0004] A major concern in solvent cleaning is the tendency (especiallywhere solvent is used at an elevated temperature) for solvent vapor lossfrom the cleaning system into the atmosphere. Although care is generallyexercised to minimize such losses (e.g., through good equipment designand vapor recovery systems), most practical cleaning applications resultin some loss of solvent vapor into the atmosphere.

[0005] Solvent cleaning processes have traditionally utilizedchlorinated solvents (e.g., chlorofluorocarbons such as1,1,2-trichloro-1,2,2-trifluoroethane and chlorocarbons such as1,1,1-trichloroethane) alone or in admixture with one or more cosolventssuch as aliphatic alcohols or other low molecular weight, polarcompounds. Such solvents were initially believed to beenvironmentally-benign, but have now been linked to ozone depletion.According to the Montreal Protocol and its attendant amendments,production and use of the solvents must be discontinued (see, e.g., P.S. Zurer, “Looming Ban on Production of CFCs, Halons Spurs Switch toSubstitutes,” Chemical & Engineering News, page 12, Nov. 15, 1993).

[0006] Thus, there has developed a need in the art for substitutes orreplacements for the commonly-used cleaning solvents. Such substitutesshould have a low ozone depletion potential, should have boiling rangessuitable for a variety of solvent cleaning applications, and should havethe ability to dissolve both hydrocarbon-based and fluorocarbon-basedsoils. Preferably, substitutes will also be low in toxicity, have noflash points (as measured by ASTM D3278-89), have acceptable stabilityfor use in cleaning applications, and have short atmospheric lifetimesand low global warming potentials.

[0007] Partially-fluorinated ethers have been suggested aschlorofluorocarbon alternatives (see, e.g., Yamashita et al.,International Conference on CFC and BFC (Halons), Shanghai, China, Aug.7-10, 1994, pages 55-58).

[0008] European Patent Publication No. 0 450 855 A2 (Imperial ChemicalIndustries PLC) describes the use of low molecular weight,fluorine-containing ethers of boiling point 20-120° C. in solventcleaning applications.

[0009] International Patent Publication No. WO 93/11280 (Allied-Signal,Inc.) discloses a non-aqueous cleaning process which utilizes afluorocarbon-based rinsing solvent.

[0010] U.S. Pat. No. 5,275,669 (Van Der Puy et al.) describeshydrofluorocarbon solvents useful for dissolving contaminants orremoving contaminants from the surface of a substrate. The solvents have4 to 7 carbon atoms and have a portion which is fluorocarbon, theremaining portion being hydrocarbon.

[0011] U.S. Pat. No. 3,453,333 (Litt et al.) discloses fluorinatedethers containing at least one halogen substituent other than fluorineand states that those ethers which are liquid can be used as solventsfor high molecular weight resinous perhalogenated compounds such assolid polychlorotrifluoroethylene resins.

[0012] French Patent Publication No. 2,287,432 (Societe Nationale desPoudres et Explosifs) describes new partially-fluorinated ethers and aprocess for their preparation. The compounds are said to be useful ashypnotic and anesthetic agents; as monomers for preparing heat-stable,fire-resistant, or self-lubricant polymers; and in phyto-sanitary andphyto-pharmaceutical fields.

[0013] German Patent Publication No. 1,294,949 (Farbwerke Hoechst AG)describes a technique for the production of perfluoroalkyl-alkyl ethers,said to be useful as narcotics and as intermediates for the preparationof narcotics and polymers.

SUMMARY OF THE INVENTION

[0014] In one aspect, this invention provides a process for removingcontaminants (e.g., hydrocarbons, fluorocarbons, or even water) from thesurface of a substrate (e.g., metal, glass, ceramic, plastic, orfabric). The process comprises contacting the substrate with (orexposing the substrate to) a liquid-and/or vapor-phase cleaningcomposition comprising at least one mono-, di-, or trialkoxy-substitutedperfluoroalkane, perfluorocycloalkane, perfluorocycloalkyl-containingperfluoroalkane, or perfluorocycloalkylene-containing perfluoroalkanecompound. The compound can optionally contain additional catenary (i.e.,in-chain) heteroatoms (e.g., oxygen or nitrogen) and preferably has aboiling point in the range of from about 25° C. to about 200° C.

[0015] The alkoxy-substituted compounds used in the process of theinvention exhibit unexpectedly high stabilities in the presence ofacids, bases, and oxidizing agents. In addition, in spite of theirfluorine content, the compounds are surprisingly good solvents forhydrocarbons (as well as fluorocarbons). The compounds are low intoxicity and flammability, have-ozone depletion potentials of zero, andhave short atmospheric lifetimes and low global warming potentialsrelative to chlorofluorocarbons and many chlorofluorocarbon substitutes.Since the compounds exhibit good solvency properties while beingenvironmentally acceptable, they satisfy the need in the art forsubstitutes or replacements for the commonly-used cleaning solventswhich have been linked to the destruction of the earth's ozone layer.

[0016] In other aspects, this invention also provides certain novelmono-, di-, and trialkoxy-substituted perfluorocompounds; a cleaningcomposition; a coating composition; and a process for depositingcoatings (e.g., coatings of lubricant) on substrate surfaces.

DETAILED DESCRIPTION OF THE INVENTION

[0017] Compounds which can be utilized in the processes of the inventionare mono-, di-, or trialkoxy-substituted perfluoroalkane,perfluorocycloalkane, perfluorocycloalkyl-containing perfluoroalkane,and perfluorocycloalkylene-containing perfluoroalkane compounds. Thecompounds include those which contain additional catenary heteroatoms(as well as those which do not) and can be utilized alone, incombination with one another, or in combination with other commoncleaning solvents (e.g., alcohols, ethers, alkanes, alkenes,perfluorocarbons, perfluorinated tertiary amines, perfluoroethers,cycloalkanes, esters, ketones, aromatics, siloxanes, hydrochlorocarbons,hydrochlorofluorocarbons, and hydrofluorocarbons). The compounds can besolids or liquids under ambient conditions of temperature and pressure,but are generally utilized for cleaning in either the liquid or thevapor state (or both). Thus, normally solid compounds can be utilizedafter tranformation to liquid and/or vapor through melting, sublimation,or dissolution in liquid co-solvent.

[0018] A class of useful alkoxy-substituted perfluorocompounds is thatwhich can be represented by the following general formula (I):

R_(f)—(O—R_(h))_(x)  (I)

[0019] wherein x is an integer of 1 to 3; when x is 1, R_(f) is selectedfrom the group consisting of linear or branched perfluoroalkyl groupshaving from 2 to about 15 carbon atoms, perfluorocycloalkyl-containingperfluoroalkyl groups having from 5 to about 15 carbon atoms, andperfluorocycloalkyl groups having from 3 to about 12 carbon atoms; whenx is 2, R_(f) is selected from the group consisting of linear orbranched perfluoroalkanediyl groups or perfluoroalkylidene groups havingfrom 2 to about 15 carbon atoms, perfluorocycloalkyl- orperfluorocycloalkylene-containing perfluoroalkanediyl orperfluoroalkylidene groups having from 6 to about 15 carbon atoms, andperfluorocycloalkanediyl groups or perfluorocycloalkylidene groupshaving from 3 to about 12 carbon atoms; when x is 3, R_(f) is selectedfrom the group consisting of linear or branched perfluoroalkanetriylgroups having from 2 to about 15 carbon atoms, perfluorocycloalkyl- orperfluorocycloalkylene-containing perfluoroalkanetriyl groups havingfrom 6 to about 15 carbon atoms, and perfluorocycloalkanetriyl groupshaving from 3 to about 12 carbon atoms; each R_(h) is independentlyselected from the group consisting of linear or branched alkyl groupshaving from 1 to about 8 carbon atoms, cycloalkyl-containing alkylgroups having from 4 to about 8 carbon atoms, and cycloalkyl groupshaving from 3 to about 8 carbon atoms; wherein either or both of thegroups R_(f) and R_(h) can contain (optionally contain) one or morecatenary heteroatoms; and wherein the sum of the number of carbon atomsin R_(f) and the number of carbon atoms in R_(h) is greater than orequal to 4. The perfluorocycloalkyl and perfluorocycloalkylene groupscontained within the perfluoroalkyl, perfluoroalkanediyl,perfluoroalkylidene and perfluoroalkanetriyl groups can optionally (andindependently) be substituted with, e.g., one or more perfluoroalkylgroups having from 1 to about 4 carbon atoms.

[0020] Preferably, x is 1; R_(f) is as defined above; R_(h) is an alkylgroup having from 1 to about 6 carbon atoms; R_(f) but not R_(h) cancontain one or more catenary heteroatoms; and the sum of the number ofcarbon atoms in R_(f) and the number of carbon atoms in R_(h) is greaterthan or equal to 4. Most preferably, x is 1; R_(f) is selected from thegroup consisting of linear or branched perfluoroalkyl groups having from3 to about 6 carbon atoms, perfluorocycloalkyl-containing perfluoroalkylor perfluoroalkylidene groups having from 5 to about 8 carbon atoms, andperfluorocycloalkyl groups having from 5 to about 6 carbon atoms; R_(h)is an alkyl group having from 1 to about 3 carbon atoms; R_(f) but notR_(h) can contain one or more catenary heteroatoms; and the sum of thenumber of carbon atoms in R_(f) and the number of carbon atoms in R_(h)is greater than or equal to 4. The perfluorocycloalkyl andperfluorocycloalkylene groups contained within the perfluoroalkyl,perfluoroalkanediyl, perfluoroalkylidene and perfluoroalkanetriyl groupscan optionally (and independently) be substituted with, e.g., one ormore perfluoromethyl groups. These compounds are preferred due to theirease of preparation and their performance characteristics.

[0021] Representative examples of alkoxy-substituted perfluorocompoundssuitable for use in the processes of the invention include the followingcompounds:

[0022] and 1,1-dimethoxyperfluorocyclohexane, where cyclic structureshaving an interior “F” are perfluorinated.

[0023] A novel subclass of the alkoxy-substituted perfluorocompounds isthat which can be represented by the following general formula (II):

R_(f) ¹—N(R_(f) ²)—C_(y)F_(2y)—O—R_(h)  (II)

[0024] wherein R_(f) ¹ and R_(f) ² are both substituted or unsubstitutedperfluoroalkyl groups having from 1 to about 6 carbon atoms or are bothsubstituted or unsubstituted perfluoroalkylene groups having from 2 toabout 4 carbon atoms, the perfluoroalkylene groups being bonded to oneanother to form a ring; y is an integer of 1 to about 8; C_(y)F_(2y) canbe linear or branched; and R_(h) is selected from the group consistingof linear or branched alkyl groups having from 1 to about 8 carbonatoms, cycloalkyl-containing alkyl groups having from 4 to about 8carbon atoms, and cycloalkyl groups having from 3 to about 8 carbonatoms; wherein the groups R_(f) ¹, R_(f) ², and R_(h) can optionally(and independently) contain one or more catenary heteroatoms.

[0025] Preferably, the perfluoroalkyl groups have from 1 to about 3carbon atoms, the perfluoroalkylene groups have from 2 to about 3 carbonatoms; y is an integer of 1 to about 3; R_(h) is selected from the groupconsisting of linear or branched alkyl groups having from 1 to about 6carbon atoms; and R_(f) ¹ and R_(f) ² but not R_(h) can independentlycontain one or more catenary heteroatoms. These compounds are preferreddue to their ease of preparation and their performance characteristics.

[0026] Representative examples of novel compounds according to FormulaII above include the following compounds:

[0027] A second novel subclass of the alkoxy-substitutedperfluorocompounds is that which can be represented by the followinggeneral formula (III):

R_(f) ³(CF₂OR_(h))_(x′)  (III)

[0028] wherein R_(f) ³ is a substituted or unsubstitutedperfluorocycloalkyl, perfluorocycloalkanediyl, orperfluorocycloalkanetriyl group having from 3 to about 12 carbon atoms;each R_(h) is independently selected from the group consisting of linearor branched alkyl groups having from 1 to about 8 carbon atoms,cycloalkyl-containing alkyl groups having from 4 to about 8 carbonatoms, and cycloalkyl groups having from 3 to about 8 carbon atoms; andx′ is an integer of 1 to 3; wherein either or both of the groups R_(f) ³and R_(h) can contain (optionally contain) one or more catenaryheteroatoms.

[0029] Preferably, R_(f) ³ has from 5 to about 6 carbon atoms; eachR_(h) is independently selected from the group consisting of linear orbranched alkyl groups having from 1 to about 6 carbon atoms; x′ is aninteger of 1 or 2; and R_(f) ³ but not R_(h) can contain one or morecatenary heteroatoms. These compounds are preferred due to their ease ofpreparation and their performance characteristics.

[0030] Representative examples of novel compounds according to FormulaIII above include the following compounds:

[0031] The alkoxy-substituted perfluorocompounds suitable for use in theprocess of the invention can be prepared by alkylation of perfluorinatedalkoxides prepared by the reaction of the corresponding perfluorinatedacyl fluoride or perfluorinated ketone with an anhydrous alkali metalfluoride (e.g., potassium fluoride or cesium fluoride) or anhydroussilver fluoride in an anhydrous polar, aprotic solvent. (See, e.g., thepreparative methods described in French Patent Publication No. 2,287,432and German Patent Publication No. 1,294,949, supra.) Alternatively, afluorinated tertiary alcohol can be allowed to react with a base, e.g.,potassium hydroxide or sodium hydride, to produce a perfluorinatedtertiary alkoxide which can then be alkylated by reaction withalkylating agent.

[0032] Suitable alkylating agents for use in the preparation includedialkyl sulfates (e.g., dimethyl sulfate), alkyl halides (e.g., methyliodide), alkyl p-toluenesulfonates (e.g., methyl p-toluenesulfonate),alkyl perfluoroalkanesulfonates (e.g., methylperfluoromethanesulfonate), and the like. Suitable polar, aproticsolvents include acyclic ethers such as diethyl ether, ethylene glycoldimethyl ether, and diethylene glycol dimethyl ether; carboxylic acidesters such as methyl formate, ethyl formate, methyl acetate, diethylcarbonate, propylene carbonate, and ethylene carbonate; alkyl nitritessuch as acetonitrile; alkyl amides such as N,N-dimethylformamide,N,N-diethylformamide, and N-methylpyrrolidone; alkyl sulfoxides such asdimethyl sulfoxide; alkyl sulfones such as dimethylsulfone,tetramethylene sulfone, and other sulfolanes; oxazolidones such asN-methyl-2-oxazolidone; and mixtures thereof.

[0033] Perfluorinated acyl fluorides (for use in preparing thealkoxy-substituted perfluorocompounds) can be prepared byelectrochemical fluorination (ECF) of the corresponding hydrocarboncarboxylic acid (or a derivative thereof), using either anhydroushydrogen fluoride (Simons ECF) or KF.2HF (Phillips ECF) as theelectrolyte. Perfluorinated acyl fluorides and perfluorinated ketonescan also be prepared by dissociation of perfluorinated carboxylic acidesters (which can be prepared from the corresponding hydrocarbon orpartially-fluorinated carboxylic acid esters by direct fluorination withfluorine gas). Dissociation can be achieved by contacting theperfluorinated ester with a source of fluoride ion under reactingconditions (see the method described in U.S. Patent No. 3,900,372(Childs), the description of which is incorporated herein by reference)or by combining the ester with at least one initiating reagent selectedfrom the group consisting of gaseous, non-hydroxylic nucleophiles;liquid, non-hydroxylic nucleophiles; and mixtures of at least onenon-hydroxylic nucleophile (gaseous, liquid, or solid) and at least onesolvent which is inert to acylating agents.

[0034] Initiating reagents which can be employed in the dissociation arethose gaseous or liquid, non-hydroxylic nucleophiles and mixtures ofgaseous, liquid, or solid, non-hydroxylic nucleophile(s) and solvent(hereinafter termed “solvent mixtures”) which are capable ofnucleophilic reaction with perfluorinated esters. The presence of smallamounts of hydroxylic nucleophiles can be tolerated. Suitable gaseous orliquid, non-hydroxylic nucleophiles include dialkylamines,trialkylamines, carboxamides, alkyl sulfoxides, amine oxides,oxazolidones, pyridines, and the like, and mixtures thereof. Suitablenon-hydroxylic nucleophiles for use in solvent mixtures include suchgaseous or liquid, non-hydroxylic nucleophiles, as well as solid,non-hydroxylic nucleophiles, e.g., fluoride, cyanide, cyanate, iodide,chloride, bromide, acetate, mercaptide, alkoxide, thiocyanate, azide,trimethylsilyl difluoride, bisulfite, and bifluoride anions, which canbe utilized in the form of alkali metal, ammonium, alkyl-substitutedammonium (mono-, di-, tri-, or tetra-substituted), or quaternaryphosphonium salts, and mixtures thereof. Such salts are in generalcommercially available but, if desired, can be prepared by knownmethods, e.g., those described by M. C. Sneed and R. C. Brasted inComprehensive Inorganic Chemistry, Volume Six (The Alkali Metals), pages61-64, D. Van Nostrand Company, Inc., New York (1957), and by H. Kobleret al. in Justus Liebigs Ann. Chem. 1978, 1937.1,4-diazabicyclo[2.2.2]octane and the like are also suitable solidnucleophiles.

[0035] The cleaning process of the invention can be carried out bycontacting a contaminated substrate with a cleaning compositioncomprising at least one of the above-described alkoxy-substitutedperfluorocompounds. The perfluorocompounds can be utilized alone or inadmixture with each other or with other commonly-used cleaning solvents,e.g., alcohols, ethers, alkanes, alkenes, perfluorocarbons,perfluorinated tertiary amines, perfluoroethers, cycloalkanes, esters,ketones, aromatics, siloxanes, hydrochlorocarbons,hydrochlorofluorocarbons, and hydrofluorocarbons. Such co-solvents canbe chosen to modify or enhance the solvency properties of a cleaningcomposition for a particular use and can be utilized in ratios (ofco-solvent to perfluorocompound(s)) such that the resulting compositionhas no flash point. Preferably, the perfluorocompound(s) used in thecomposition have boiling points in the range of from about 25° C. toabout 200° C., more preferably from about 25° C. to about 125° C.

[0036] To remove soils from fiber and textile substrates, the cleaningprocess of the invention can be carried out by contacting the fiber ortextile with a cleaning composition comprising an alkoxy-substitutedperfluoroalkane at ambient or elevated temperatures. The soiled textilecan be agitated to promote the dissolving, dispersing or displacing ofsoil using any conventional agitation means including shaking, stirringand ultrasonic agitation. When the textile is sufficiently cleaned, thecleaning composition may be removed (e.g. by decantation), the textileoptionally rinsed using an alkoxy-substituted perfluoroalkane or anyconventional dry-cleaning solvent to ensure soil removal and preventredeposition, and the textile can be dried, for example, by air-dryingwith or without added heat.

[0037] Optionally and preferably, the cleaning composition furthercomprises a surfactant. Suitable surfactants include those surfactantsthat are sufficiently soluble in the alkoxy-substituted perfluoroalkane,and which promote soil removal by dissolving, dispersing or displacingthe soil. One useful class of surfactants are those nonionic surfactantsthat have a hydrophilic-lipophilic balance (HLB) value of less thanabout 14. Examples include ethoxylated alcohols, ethoxylatedalkylphenols, ethoxylated fatty acids, alkylaryl sulfonates, glycerolesters, ethoxylated fluoroalcohols, and fluorinated sulfonamides.Mixtures of surfactants having complementary properties may be used inwhich one surfactant is added to the cleaning composition to promoteoily soil removal and another added to promote water-soluble soilremoval.

[0038] The surfactant, if used, can be added in an amount sufficient topromote soil removal. Typically, surfactant is added in amounts fromabout 0.1 to 5.0 wt. %, preferably in amounts from about 0.2 to 2.0 wt.% of the cleaning composition.

[0039] The cleaning composition can be used in either the gaseous or theliquid state (or both), and any of the known techniques for “contacting”a substrate can be utilized. For example, a liquid cleaning compositioncan be sprayed or brushed onto the substrate, a gaseous cleaningcomposition can be blown across the substrate, or the substrate can beimmersed in either a gaseous or a liquid composition. Elevatedtemperatures, ultrasonic energy, and/or agitation can be used tofacilitate the cleaning. Various different solvent cleaning techniquesare described by B. N. Ellis in Cleaning and Contamination ofElectronics Components and Assemblies, Electrochemical PublicationsLimited, Ayr, Scotland, pages 182-94 (1986).

[0040] Both organic and inorganic substrates can be cleaned by theprocess of the invention. Representative examples of the substratesinclude metals; ceramics; glass; polycarbonate; polystyrene;acrylonitrile-butadiene-styrene copolymer; synthetic non-wovenmaterials; natural fibers (and fabrics derived therefrom) such ascotton, silk, fur, suede, leather, linen, and wool; synthetic fibers(and fabrics) such as polyester, rayon, acrylics, nylon, and blendsthereof; fabrics comprising a blend of natural and synthetic fibers; andcomposites of the foregoing materials. The process is especially usefulin the precision cleaning of electronic components (e.g., circuitboards), optical or magnetic media, and medical devices.

[0041] The cleaning process of the invention can be used to dissolve orremove most contaminants from the surface of a substrate. For example,materials such as light hydrocarbon contaminants; higher molecularweight hydrocarbon contaminants such as mineral oils and greases;fluorocarbon contaminants such as perfluoropolyethers,bromotrifluoroethylene oligomers (gyroscope fluids), andchlorotrifluoroethylene oligomers (hydraulic fluids, lubricants);silicone oils and greases; solder fluxes; particulates; and othercontaminants encountered in precision, electronic, metal, and medicaldevice cleaning can be removed. The process is particularly useful forthe removal of hydrocarbon contaminants (especially, light hydrocarbonoils), fluorocarbon contaminants, particulates, and water (as describedin the next paragraph).

[0042] To displace or remove water from substrate surfaces, the cleaningprocess of the invention can be carried out as described in U.S. Pat.No. 5,125,978 (Flynn et al.) by contacting the surface of an articlewith a liquid cleaning composition which preferably contains a non-ionicfluoroaliphatic surface active agent. The wet article is immersed in theliquid composition and agitated therein, the displaced water isseparated from the liquid composition, and the resulting water-freearticle is removed from the liquid composition. Further description ofthe process and the articles which can be treated are found in said U.S.Pat. No. 5,125,978, which description is incorporated herein byreference. The process can also be carried out as described in U.S. Pat.No. 3,903,012 (Brandreth), the description of which is also incorporatedherein.

[0043] This invention also provides a cleaning composition comprising(a) a major amount (preferably, at least about 60 percent of thecomposition by weight) of at least one mono-, di-, ortrialkoxy-substituted perfluoroalkane, perfluorocycloalkane,perfluorocycloalkyl-containing perfluoroalkane, orperfluorocycloalkylene-containing perfluoroalkane compound, the compoundoptionally containing additional catenary heteroatoms; and (b) a minoramount of at least one co-solvent selected from the group consisting ofalcohols, ethers, alkanes, alkenes, perfluorocarbons, perfluorinatedtertiary amines, perfluoroethers, cycloalkanes, esters, ketones,aromatics, siloxanes, hydrochlorocarbons, hydrochlorofluorocarbons, andhydrofluorocarbons. Preferably, the co-solvent is selected from thegroup consisting of alcohols, alkanes, alkenes, cycloalkanes, esters,aromatics, hydrochlorocarbons, and hydrofluorocarbons.

[0044] Representative examples of co-solvents which can be used in thecleaning composition include methanol, ethanol, isopropanol, t-butylalcohol, methyl t-butyl ether, methyl t-amyl ether, 1,2-dimethoxyethane,cyclohexane, 2,2,4-trimethylpentane, n-decane, terpenes (e.g., a-pinene,camphene, and limonene), trans-1,2-dichloroethylene, methylcyclopentane,decalin, methyl decanoate, t-butyl acetate, ethyl acetate, diethylphthalate, 2-butanone, methyl isobutyl ketone, naphthalene, toluene,p-chlorobenzotrifluoride, trifluorotoluene, hexamethyl disiloxane,octamethyl trisiloxane, perfluorohexane, perfluoroheptane,perfluorooctane, perfluorotributylamine, perfluoro-N-methyl morpholine,perfluoro-2-butyl oxacyclopentane, methylene chloride,chlorocyclohexane, 1-chlorobutane, 1,1-dichloro-1-fluoroethane,1,1,1-trifluoro-2,2-dichloroethane,1,1,1,2,2-pentafluoro-3,3-dichloropropane,1,1,2,2,3-pentafluoro-1,3-dichloropropane, 2,3-dihydroperfluoropentane,1,1,1,2,2,4-hexafluorobutane,1-trifluoromethyl-1,2,2-trifluorocyclobutane,3-methyl-1,1,2,2-tetrafluorocyclobutane, and1-hydropentadecafluoroheptane.

[0045] The above-described alkoxy-substituted perfluorocompounds can beuseful not only in cleaning but also in coating deposition, where theperfluorocompound functions as a carrier for a coating material toenable deposition of the material on the surface of a substrate. Theinvention thus also provides a coating composition and a process fordepositing a coating on a substrate surface using the composition. Theprocess comprises the step of applying to at least a portion of at leastone surface of a substrate a coating of a liquid coating compositioncomprising (a) a solvent composition comprising at least one mono-, di-,or trialkoxy-substituted perfluoroalkane, perfluorocycloalkane,perfluorocycloalkyl-containing perfluoroalkane, orperfluorocycloalkylene-containing perfluoroalkane compound, the compoundoptionally containing additional catenary heteroatoms; and (b) at leastone coating material which is soluble or dispersible in the solventcomposition. The solvent composition can further comprise one or moreco-dispersants or co-solvents (as defined supra, preferably those havingboiling points below about 125° C.) and/or one or more additives (e.g.,surfactants, coloring agents, stabilizers, anti-oxidants, flameretardants, and the like). Preferably, the process further comprises thestep of removing the solvent composition from the coating by, e.g.,allowing evaporation (which can be aided by the application of, e.g.,heat or vacuum).

[0046] Coating materials which can be deposited by the process includepigments, lubricants, stabilizers, adhesives, anti-oxidants, dyes,polymers, pharmaceuticals, release agents, inorganic oxides, and thelike, and combinations thereof. Preferred materials includeperfluoropolyether, hydrocarbon, and silicone lubricants; amorphouscopolymers of tetrafluoroethylene; polytetrafluoroethylene; andcombinations thereof. Representative examples of materials suitable foruse in the process include titanium dioxide, iron oxides, magnesiumoxide, perfluoropolyethers, polysiloxanes, stearic acid, acrylicadhesives, polytetrafluoroethylene, amorphous copolymers oftetrafluoroethylene, and combinations thereof. Any of the substratesdescribed above (for cleaning applications) can be coated via theprocess of the invention. The process can be particularly useful forcoating magnetic hard disks or electrical connectors withperfluoropolyether lubricants or medical devices with siliconelubricants.

[0047] To form a coating composition, the components of the composition(i.e., the alkoxy-substituted perfluorocompound(s), the coatingmaterial(s), and any co-dispersant(s) or co-solvent(s) utilized) can becombined by any conventional mixing technique used for dissolving,dispersing, or emulsifying coating materials, e.g., by mechanicalagitation, ultrasonic agitation, manual agitation, and the like. Thesolvent composition and the coating material(s) can be combined in anyratio depending upon the desired thickness of the coating, but thecoating material(s) preferably constitute from about 0.1 to about 10weight percent of the coating composition for most coating applications.

[0048] The deposition process of the invention can be carried out byapplying the coating composition to a substrate by any conventionaltechnique. For example, the composition can be brushed or sprayed (e.g.,as an aerosol) onto the substrate, or the substrate can be spin-coated.Preferably, the substrate is coated by immersion in the composition.Immersion can be carried out at any suitable temperature and can bemaintained for any convenient length of time. If the substrate is atubing, such as a catheter, and it is desired to ensure that thecomposition coats the lumen wall, it may be advantageous to draw thecomposition into the lumen by the application of reduced pressure.

[0049] After a coating is applied to a substrate, the solventcomposition can be removed from the coating by evaporation. If desired,the rate of evaporation can be accelerated by application of reducedpressure or mild heat. The coating can be of any convenient thickness,and, in practice, the thickness will be determined by such factors asthe viscosity of the coating material, the temperature at which thecoating is applied, and the rate of withdrawal (if immersion isutilized).

[0050] Objects and advantages of this invention are further illustratedby the following examples, but the particular materials and amountsthereof recited in these examples, as well as other conditions anddetails, should not be construed to unduly limit this invention.

EXAMPLES

[0051] The environmental impact of the alkoxy-substitutedperfluorocompounds used in the processes and compositions of theinvention was assessed by determination of the atmospheric lifetime andthe global warming potential (GWP) of certain compounds, as describedbelow:

[0052] Atmospheric Lifetime

[0053] The atmospheric lifetime (t_(sample)) of various sample compoundswas calculated by the technique described in Y. Tang, Atmospheric Fateof Various Fluorocarbons, M. S. Thesis, Massachusetts Institute ofTechnology (1993). According to this technique, an ultraviolet (UV) gascell was charged with a sample compound, a reference compound (eitherCH₄ or CH₃Cl), ozone, and water vapor. Hydroxyl radicals were thengenerated by photolytic decomposition of the ozone in the presence ofthe water vapor and an inert buffer gas, i.e., helium. As the samplecompounds and reference compounds reacted with the hydroxyl radicals inthe gas phase, their concentrations were measured by Fourier transforminfrared spectroscopy (FTIR). The rate constant for reaction of thesample compound (k_(sample)) with hydroxyl radical was measured relativeto the rate constant for a reference compound (k_(ref)), and theatmospheric lifetime was then calculated using the following formula(where t_(CH4) and k_(CH4) are known values):$\tau_{sample} = \frac{\tau_{CH4}}{\left( \frac{k_{sample}}{k_{ref}} \right)\left( \frac{k_{ref}}{k_{CH4}} \right)}$

[0054] The rate constant for each sample compound was measured (usingCH₄ as the reference compound and again using CH₃Cl) at 298K, and theatmospheric lifetime values were calculated and then averaged. Theresults are shown in Table A under the heading “Atmospheric Lifetime.”For comparative purposes, the atmospheric lifetime for severalhydrofluorocarbons is also shown in Table A.

[0055] Atmospheric lifetime was also estimated from a correlationdeveloped between the highest occupied molecular orbital (HOMO) energyand the known atmospheric lifetimes of hydrofluorocarbons andhydrofluorocarbon ethers, in a manner similar to that described byCooper et al. in Atmos. Environ. 26A, 7, 1331 (1992). The correlationdiffered from that found in Cooper et al. in the following respects: thecorrelation was developed using a larger data set; lifetimes for thecorrelations were determined by relative hydroxyl reactivity of thesample to CH₃CCl₃ at 277K, as described by Zhang et al. in J. Phys.Chem. 98(16), 4312 (1994); HOMO energy was calculated using MOPAC/PM3, asemi-empirical molecular orbital package; and the number of hydrogenatoms present in the sample was included in the correlation. The resultsare reported in Table A under the heading “Estimated AtmosphericLifetime.”

[0056] Global Warming Potential

[0057] Global warming potential (GWP) was determined for the varioussample compounds using the above-described calculated values foratmospheric lifetime and experimentally determined infrared absorbancedata integrated over the spectral region of interest, typically 500 to2500 cm^(—1). The calculations were based on the definition of GWP setforth by the Intergovernmental Panel in Climate Change in ClimateChange: The IPCC Scientific Assessment, Cambridge University Press(1990). According to the Panel, GWP is the integrated potential warmingdue to the release of 1 kilogram of sample compound relative to thewarming due to 1 kilogram of CO₂ over a specified integration timehorizon (ITH) using the following equation:${GWP}_{sample} = \frac{\int\limits_{0}^{ITH}{\Delta \quad T_{x}C_{\theta 0x}^{{{- t}/\tau}\quad x}{t}}}{\int\limits_{0}^{ITH}{\Delta \quad T_{{CO}_{2}}C_{{CO}_{2}}{t}}}$

[0058] where ΔT is the calculated change in temperature at the earth'ssurface due to the presence of a particular compound in the atmosphere[calculated using a spreadsheet model (using parameters described byFisher et al. in Nature 344, 513 (1990)) derived from Atmospheric andEnvironmental Research, Inc.'s more complete one-dimensionalradiative-convective model (described by Wang et al. in J. Atmos. Sci.38, 1167 (1981) and J. Geophys. Res. 90, 12971 (1985)], C is theatmospheric concentration of the compound, t is the atmospheric lifetimeof the compound (the calculated value described above), and x designatesthe compound of interest. Upon integration, the formula is as follows:

[0059] where A₁=0.30036, A₂=0.34278, A₃=0.35686, τ₁=6.993, τ₂71.108, andρ₃815.73 in the Siegenthaler${GWP}_{sample} = \frac{\Delta \quad T_{x}C_{ox}{\tau_{x}\left\lbrack {1 - e^{{{- {ITH}}/\tau}\quad x}} \right\rbrack}}{\begin{matrix}{\Delta \quad {{T_{{CO}_{2}}\left( {{1 \cdot 3}{x10}^{- 10}} \right)}\left\lbrack {{A_{1{\tau 1}}\left( {1 - e^{{- {ITH}}/{\tau 1}}} \right)} +} \right.}} \\\left. {{A_{2{\tau 2}}\left( {1 - e^{{- {ITH}}/{\tau 2}}} \right)} + {A_{3{\tau 3}}\left( {1 - e^{{- {ITH}}/{\tau 3}}} \right)}} \right\rbrack\end{matrix}}$

[0060] (1983) coupled ocean-atmosphere CO₂ model. The results of thecalculations are shown in Table A below. TABLE A Global EstimatedWarming Atmospheric Atmospheric Potential Lifetime Lifetime (100 yearCompound (years) (years) ITH) CF₃-CH₃ 62.2 CF₃-O-CH₃ 1.6 C₂F₅-CH₃ 12.6C₂F₅-O-CH₃ 1.6 C₃F₇-CH₃ 9.6 C₃F₇-O-CH₃ 1.9 C₄F₉-CH₃ 7.0 C₄F₉-O-CH₃ 1.95.5 330 C₄F₉-C₂H₅ 2.0 C₄F₉-O-C₂H₅ 0.5 1.2 70 C₅F₁₁OCH₃ 4.3CF₃CF(OCH₃)CF(CF₃)₂ 4-5 C₅F₁₁OC₂H₅ ˜1 c-C₆F₁₁-CH₃ 13.7 c-C₆F₁₁-O-CH₃ 1.83.8 170 C₂F₅CF(OCH₃)CF(CF₃)₂ 4-5 CF₃CFHCFHCF₂CF₃ 23* 1000

[0061] As can be seen in Table A, each of the various alkoxy-substitutedperfluorocompounds unexpectedly has a lower atmospheric lifetime thanthe corresponding hydrofluorocarbon, i.e., the hydrofluorocarbon havingthe same carbon number. The alkoxy-substituted perfluorocompounds arethus more environmentally acceptable than the hydrofluorocarbons (whichhave previously been proposed as chlorofluorocarbon replacements).

[0062] The chemical stability of the alkoxy-substitutedperfluorocompounds used in the processes and compositions of theinvention was also evaluated to determine their suitability for use incleaning and coating applications. In these tests, a compound wascontacted with a chemical agent such as aqueous sodium acetate, aqueousKOH, concentrated sulfuric acid, or potassium permanganate in acetone todetermine the stability of the compound to base, acid, or oxidant, asdescribed below:

[0063] Stability in the Presence of Base

[0064] To assess hydrolytic stability, a ten gram sample ofalkoxy-substituted perfluorocompound was combined with 10 g of 0.1MNaOAc and sealed in a 2.54 cm (internal diameter) by 9.84 cm Monel™ 400alloy (66% nickel, 31.5% copper, and 1.2% iron and several minorcomponents) tube (available from Paar Instrument Co. of Moline, Ill. asPart Number 4713 cm). The tube was heated at 110° C. in a forced airconvection oven for 16 hours. After cooling to room temperature, a 1 mLsample of the tube contents was diluted with 1 mL of total ionicstrength adjustment buffer (TISAB, available from Orion Research, Inc.,a mixture of 1,2-cyclohexylene dinitrilotetraacetic acid, deionizedwater, sodium acetate, sodium chloride, and acetic acid). Theconcentration of fluoride ion (resulting from any reaction of theperfluorocompound with the aqueous NaOAc) was measured using an OrionModel 720A Coulombmeter with a F⁻ specific electrode which had beenpreviously calibrated using 0.5 and 500 ppm F⁻ solutions. Based on themeasured fluoride ion concentration, the rate at which HF had beengenerated by reaction of the aqueous NaOAc with the perfluorocompoundwas calculated. The results are shown below in Table B and indicate thatthe alkoxy-substituted perfluorocompounds are much more stable to basethan is the comparative compound. TABLE B C₄F₉OCH₃ C₄F₉OC₂H₅ c-C₆F₁₁OCH₃CF₃CFHCFHCF₂CF₃ HF 0.67 0.22 0.33 42.9 Generation Rate (μg/g/hr)

[0065] To assess hydrolytic stability under more severely basicconditions, C₄F₉OCH₃ (125 g of 99.8% purity, 0.5 mole) was combined withpotassium hydroxide (29.4 g, 0.45 mole, dissolved in 26.1 g water) in a250 mL flask equipped with an overhead stirrer, a condenser, and athermometer, and the resulting solution was refluxed at 58° C. for 19hours. Water (50 mL) was added to the solution after refluxing, and theresulting product was distilled. The lower fluorochemical phase of theresulting distillate was separated from the upper phase and was washedwith water (100 mL) to yield 121.3 g of recovered C₄F₉OCH₃, which wasidentical in purity and composition to the starting material (as shownby gas chromatography). The aqueous base solution remaining in thereaction flask was titrated with standard 1.0 N HCl to reveal that noneof the KOH originally charged had been consumed, indicating that theperfluorocompound was stable in the presence of the base.

[0066] Stability in the Presence of Acid

[0067] To assess hydrolytic stability under acidic conditions, C₄F₉OCH₃(15 g, 0.06 mole) was combined with sulfuric acid (10 g of 96% byweight, 0.097 mole) in a 50 mL flask containing a stir bar and fittedwith a reflux condenser. The resulting mixture was stirred for 16 hoursat room temperature, and then the resulting upper fluorochemical phasewas separated from the resulting lower sulfuric acid phase. Gas-liquidchromatographic (GLC) analysis of the fluorochemical phase revealed thepresence of only the starting perfluorocompound and no detectable amountof C₃F₇CO₂CH₃, the expected product of hydrolysis. This result(indicating that the perfluorocompound was stable in the presence of theacid) was surprising in view of the discussion by England in J.Org.Chem. 49, 4007 (1984), which states that “[f]luorine atoms attached tocarbon which also bears an alkyl ether group are known to be labile toelectrophilic reagents. They are readily hydrolyzed in concentratedsulfuric acid, thus providing a route to some esters of fluoroacids.”

[0068] Stability in the Presence of Oxidant

[0069] To assess oxidative stability, potassium permanganate (20 g,0.126 mole) was dissolved in acetone, and C₄F₉OCH₃ (500 g of 99.9%purity, 2.0 mole) was added to the resulting solution. The solution wasrefluxed for four hours, with no indication that the permanganate hadbeen consumed (as evidenced by the absence of brown MnO₂). The refluxedsolution was then distilled into a 500 mL Barrett trap filled withwater. The lower fluorochemical phase of the resulting mixture wasseparated from the upper phase, was washed with four 1.5 L aliquots ofwater, and was dried by passage through a column of silica gel to yield471 g of resulting product. Gas chromatographic analysis of the productrevealed no evidence of degradation of the starting perfluorocompound,indicating that the compound was stable in the presence of the oxidant.

[0070] Flash Point Testing

[0071] The alkoxy-substituted perfluorocompounds C₄F₉OCH₃, C₄F₉OC₂H₅,and c-C₆F₁₁OCH₃ were tested for flash point by the standard methoddefined by ASTM D3278-89. Each compound was determined to have no flashpoint.

Examples 1-7 Describe the Preparation of Novel Alkoxy-substitutedPerfluorocompounds of the Invention Example 1

[0072] Preparation of c-C₆F₁₁CF₂OC₂H₅

[0073] A one liter jacketed round bottom flask was equipped with areflux condenser, an overhead stirrer, and an addition funnel. The flaskwas charged with anhydrous dimethyl formamide (300 g) and diethylsulfate (239 g, 1.55 mole) under a flow of dry nitrogen gas. Theresulting stirred solution was cooled to −20° C., and spray-driedpotassium fluoride (Aldrich Chemical, which was further dried at 120°C., 67.5 g, 1.16 mole) was added. A mixture of perfluorocyclohexanecarbonyl fluoride and isomers of perfluoro methylcyclopentane carbonylfluoride (approximately 800 purity, 318 g, 0.77 mole) was then added tothe resulting mixture over a period of 45 minutes. (Hereinafter,c-C₆F₁₁-refers to a mixture of the perfluorinated cyclohexyl and methylcyclopentyl isomers.) The mixture was held at −20° C. for two hours andthen allowed to come to ambient temperature while stirring overnight.The mixture was transferred to a two liter round bottom flask and washeated to 50° C. for one hour. One liter of water was added and theresulting mixture distilled. The lower fluorochemical phase of theresulting distillate was then separated from the upper phase and waswashed once with water to afford 236 g of 61.9% purity c-C₆F₁₁CF₂OC₂H₅.The product was distilled to a purity of 99% (b.=128-134° C.). Theproduct identity was confirmed by gas chromatography/ mass spectrometry(GCMS) and by ¹H and ¹⁹F nuclear magnetic resonance spectroscopy (NMR).

Example 2

[0074] Preparation of c-C₆F₁₁CF₂OCH₃

[0075] A 500 mL round bottom flask was equipped with an overheadstirrer, a condenser, and an addition funnel, and was then charged withspray-dried potassium fluoride (Aldrich, which was further dried at 120°C., 39.8 g, 0.68 mole) and anhydrous dimethyl formamide (250 g).c-C₆F₁₁COF (150 g of 70% purity, 0.32 mole) was added slowly to theresulting mixture at room temperature. An ice bath was then placedaround the flask, and dimethyl sulfate (74.8 g, 0.59 mole) was addeddropwise. The resulting mixture was held in the ice bath for five hours,followed by warming to ambient temperature with stirring overnight.Water (100 mL) was then added to the mixture, and the resulting productwas distilled. The lower fluorochemical phase of the resultingdistillate was separated from the upper aqueous phase to yield 143 g ofc-C₆F₁₁CF₂OCH₃ of 63% purity. The products of several reactions werecombined and distilled (b.=110-120° C.). The product identity wasconfirmed by GCMS and by ¹H and ¹⁹F NMR.

Example 3

[0076] Preparation of 4-CF₃-c-C₆F₁₀CF₂OCH₃

[0077] A one liter round bottom flask was equipped with an overheadstirrer, a condenser, and an addition funnel and was then charged withspray-dried potassium fluoride (Aldrich, which was further dried at 120°C., 15.4 g, 0.26 mole), anhydrous cesium fluoride (6.5 g, 0.043 mole),and anhydrous dimethyl formamide (250 g). A mixture ofperfluoro-4-methylcyclohexane carbonyl fluoride and perfluorodimethylcyclopentane carbonyl fluorides (100 g of 72% purity, 0.189 mole) wasthen added to the resulting mixture, and the mixture was stirred atambient temperature for four hours. Dimethyl sulfate (33.3 g, 0.264mole) was then added to the stirred mixture, and the mixture was furtherstirred for 72 hours followed by addition of water (500 mL).

[0078] The mixture was worked up essentially as described in Example 1to yield 67 g of a mixture of several components, which was subsequentlydistilled to give 26.5 g of 4-CF₃-c-C₆F₁₀CF₂OCH₃ (b.=118-137° C.) of 88%purity. The product identity was confirmed by GCMS and by ¹H and ¹⁹FNMR, which showed the product to be about 60% of the trans-1,4 isomerand 15% of the cis-1,4 isomer. The product also contained several otherisomers of CF₃-c-C₆F₁₀CF₂OCH₃, resulting from isomers of theperfluoromethylcyclohexane carbonyl fluoride which were present in thestarting material.

Example 4

[0079] Preparation of

[0080] The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (27 g, 0.46 mole), anhydrous dimethylformamide (250 g), perfluoro-3-piperidinopropionyl fluoride (322 g of40.4% purity, 0.32 mole), and dimethyl sulfate (52 g, 0.41 mole). 275 gof a product mixture of 38% purity was obtained, which was fractionallydistilled to give a main fraction of the desired compound (b.=137-139°C., 91% purity). The product identity was confirmed by infraredspectroscopy (IR), GCMS, and ¹H and ¹⁹F NMR.

Example 5

[0081] Preparation of

[0082] The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (42 g, 0.72 mole), anhydrous dimethylformamide (300 g), perfluoro-2-piperidinoacetyl fluoride (354 g of 47.2%purity, 0.46 mole), and diethyl sulfate (94 g, 0.61 mole). 349 g of aproduct mixture of 39% purity was obtained, which was fractionallydistilled to give a main fraction of the desired compound (b.=135-137°C.). The product identity was confirmed by IR, GCMS, and ¹H and ¹⁹F NMR.

Example 6

[0083] Preparation of

[0084] The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (17.7 g, 0.30 mole), anhydrous dimethylformamide (300 g), perfluoro-3-morpholinopropionyl fluoride (890 g of8.6% purity, 0.2 mole), and dimethyl sulfate (37 g, 0.29 mole). 88 g ofa product mixture of 57% purity was obtained, which was fractionallydistilled to give a main fraction of the desired compound (b.p.=129° C.,90% purity). The product identity was confirmed by IR, GCMS, and ¹H and3⁹F NMR.

Example 7

[0085] Preparation of CH₃OCF₂-c-C₆F₁₀CF₂OCH₃

[0086] The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (6.62 g, 0.011 mole), anhydrous dimethylformamide (200 g), FCO-c-C₆F₁₀COF (253 g of approximately 26% purity,0.185 mole; the remainder-of the material comprised a mixture ofmono-functional, non-functional, and isomeric compounds), and dimethylsulfate (14.4 g, 0.011 mole). 21 g of solid CH₃OCF₂-c-C₆F₁₀CF₂OCH₃ wasobtained (product identity confirmed by IR and ¹H and ¹⁹F NMR).

Examples 8-28 Describe the Use of Alkoxy-substituted Perfluorocompoundsin Various Different Cleaning Applications According to the CleaningProcess of the Invention

[0087] A number of different alkoxy-substituted perfluorocompounds wereprepared for use in cleaning, as described below:

[0088] Preparation of C₄F₉OC₂H₅

[0089] A 20 gallon Hastalloy C reactor, equipped with a stirrer and acooling system, was charged with spray-dried potassium fluoride (7.0 kg,120.3 mole). The reactor was sealed, and the pressure inside the reactorwas reduced to less than 100 torr. Anhydrous dimethyl formamide (22.5kg) was then added to the reactor, and the reactor was cooled to below0° C. with constant agitation. Heptafluorobutyryl fluoride (22.5 kg of58% purity, 60.6 mole) was added to the reactor contents. When thetemperature of the reactor reached −20° C., diethyl sulfate (18.6 kg,120.8 mole) was added to the reactor over a period of approximately twohours. The resulting mixture was then held for 16 hours with continuedagitation, was raised to 50° C. for an additional four hours tofacilitate complete reaction, and was cooled to 20° C. Then, volatilematerial (primarily perfluorooxacyclopentane present in the startingheptafluorobutyryl fluoride) was vented from the reactor over athree-hour period. The reactor was then resealed, and water (6.0 kg) wasadded slowly to the reactor. After the exothermic reaction of the waterwith unreacted perfluorobutyryl fluoride subsided, the reactor wascooled to 25° C., and the reactor contents were stirred for 30 minutes.The reactor pressure was carefully vented, and the lower organic phaseof the resulting product was removed to afford 17.3 kg of material whichwas 73% C₄F₉OC₂H₅ (b.p.=75° C.) The product identity was confirmed byGCMS and by ¹H and ⁹F NMR.

[0090] Preparation of C₄F,OCH₃

[0091] The reaction was carried out in the same equipment and in asimilar manner to the procedure of Example 7 above, but using thefollowing materials: spray-dried potassium fluoride (6 kg, 103.1 mole),anhydrous dimethyl formamide (25.1 kg), perfluorobutyryl fluoride (58%purity, 25.1 kg, 67.3 mole), and dimethyl sulfate (12.0 kg, 95.1 mole).22.6 kg of product was obtained, which was 63.2% C₄F₉OCH₃ (b.=58-60°C.). The product identity was confirmed by GCMS and by ¹H and ¹⁹F NMR.

[0092] Preparation of c-C₆F₁₁OCH₃

[0093] A 500 ml, 3-necked round bottom flask equipped with an overheadstirrer, an addition funnel, and a condenser was charged with anhydrouscesium fluoride (27.4 g, 0.18 mole), anhydrous diethylene glycoldimethyl ether (258 g, hereinafter diglyme), and dimethyl sulfate (22.7g, 0.18 mole). Perfluorocyclohexanone (50g, 0.18 mole) was then addeddropwise to the resulting stirred mixture, and stirring was continuedfor 18 hours after the addition. Water (approximately 200 ml) was addedto the resulting mixture, and the lower fluorochemical phase of themixture was separated from the upper phase and washed once withsaturated aqueous sodium chloride solution. Since the fluorochemicalphase still contained about 12% diglyme, water was added to it, and theresulting product was azeotropically distilled to yield 32.8 g ofc-C₆F₁₁OCH₃ (b.p.=100° C.), which was free of diglyme. The productidentity was confirmed by IR, GCMS, and ¹H and 19F NMR.

[0094] Preparation of (CF₃)₂CFCF₂OCH₃

[0095] The title compound was prepared essentially as in Example 1 usinganhydrous potassium fluoride (31.9 g, 0.55 mole), anhydrous dimethylformamide (186 g), perfluoroisobutryl fluoride (108 g of 99% purity, 0.5mole), and dimethyl sulfate (81.9 g, 0.65 mole). The resulting mixturewas held at −20° C. for 16 hours, was warmed to 40° C. for 3.5 hours,and was then distilled to yield 109 g of the title compound (83.6%purity by GLC; also containing 11.6% (CF₃)₂CFCOF). The reaction mixturesfrom several runs were combined and distilled (b.=60-61° C.).

[0096] Preparation of (CF₃)2CFCF₂OC₂H₅

[0097] The title compound was prepared essentially as in Example 1 usinganhydrous potassium fluoride (31.9 g, 0.55 mole), anhydrous dimethylformamide (184 g), perfluoroisobutryl fluoride (112.3 g of 77% purity,0.4 mole), and diethyl sulfate (100.1 g, 0.65 mole). The resultingmixture was worked up essentially as in Example 3 to yield 80 g of thetitle compound. The product identity was confirmed by IR, GCMS, and ¹Hand ¹⁹F NMR.

[0098] Preparation of C₈F₁₇OCH₃

[0099] The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (6.62 g, 0.011 mole), anhydrous dimethylformamide (800 g), C₇F₁₅COF (456.7 g, 1.09 mole), and dimethyl sulfate(14.4 g, 0.011 mole). The resulting mixture was worked up essentially asin Example 3 to give 444 g of the title compound (99.7w purity,b.=142-144° C.). The product identity was confirmed by IR, GCMS, and ¹Hand ¹⁹F NMR.

[0100] Preparation of C₂F₅CF(OCH₃)CF(CF₃)₂

[0101] The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (7.2 g, 0.123 mol), anhydrous diethyleneglycol dimethyl ether (diglyme, 60 g), methyltrialkyl(C₈-C₁₀)ammoniumchloride (Adogen™ 464, available from Aldrich Chemical Company, 1.8 g),C₂F₅COCF(CF₃)₂ (30 g, 0.095 mol, prepared by the reaction ofpentafluoropropionyl fluoride with KF and hexafluoropropene), anddimethyl sulfate (15.5 g, 0.123 mol). The reaction mixture was stirredat room temperature for 72 hours. Approximately 100 mL of 10% aqueouspotassium hydroxide was then added to the reaction mixture, and theresulting product was azeotropically distilled from the mixture. Thelower phase of the resulting distillate was separated from the upperphase, was washed with water, and was distilled to give 26.7 g ofproduct ether (boiling range 90-92° C.; >99% purity by gas-liquidchromatography (GLC)). The product identity was confirmed by GCMS and ¹Hand ¹⁹F NMR.

[0102] Preparation of C₃F₇OCH₃

[0103] A jacketed one liter round bottom flask was equipped with anoverhead stirrer, a solid carbon dioxide/acetone condenser, and anaddition funnel. The flask was charged with spray-dried potassiumfluoride (85 g, 1.46 mol) and anhydrous diethylene glycol dimethyl ether(375 g) and was then cooled to about −20° C. using a recirculatingrefrigeration system. C₂F₅COF (196 g, 1.18 mol) was added to the flaskover a period of about one hour. The flask was then warmed to about 24°C., and dimethyl sulfate (184.3 g, 1.46 mol) was then added dropwise viathe addition funnel over a 45 minute period. The resulting mixture wasthen stirred at room temperature overnight. Water (a total of 318 mL)was then added dropwise to the mixture. The mixture was transferred to aone liter round bottom flask, and the resulting product ether wasazeotropically distilled. The lower product phase of the resultingdistillate was separated from the upper aqueous phase, was washed oncewith cold water, and was subsequently distilled to give 180 g of product(b.p. 360° C.; >99.9% purity by GLC). The product identity was confirmedby GCMS and by ¹H and ¹⁹F NMR.

[0104] Preparation of CF₃CF(OCH₃)CF(CF₃)₂

[0105] The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (12.8 g, 0.22 mol), anhydrous diethyleneglycol dimethyl ether (diglyme, 106 g), methyltrialkyl(C₈-C₁₀)ammoniumchloride (Adogen™ 464, available from Aldrich Chemical Company, 4 g),CF₃COCF(CF₃)₂ (53.2 g, 0.20 mol, prepared essentially by the procedureof Smith et al., J. Am. Chem. Soc., 84, 4285 (1962)), and dimethylsulfate (33.9 g, 0.72 mol). Aqueous potassium hydroxide was added to thereaction mixture (approximately 25 g of 50% solution), followed by water(200 mL). The resulting crude product was azeotropically distilled fromthe reaction mixture. The lower phase of the resulting distillate wasseparated from the upper phase, was washed with water, was dried overanhydrous sodium sulfate, and was distilled (b.p. 82-83° C.; yield of 45g). The product identity was confirmed by GCMS and by FTIR.

[0106] Preparation of C₅F₁₁OCH₃

[0107] The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (32 g, 0.55 mol), anhydrous diethyleneglycol dimethyl ether (diglyme, 375 g), methyltrialkyl(C₈-C₁₀)ammoniumchloride (Adogen™ 464, available from Aldrich Chemical Company, 12.5 g),C₄F₉COF (218 g of 60.7% purity, 0.5 mol), and dimethyl sulfate (69.3 g,0.55 mol). The reaction mixture was stirred at room temperatureovernight. Approximately 100 mL of 10% aqueous potassium hydroxide wasthen added to the mixture, and the resulting product was azeotropicallydistilled from the mixture. The lower phase of the resulting distillatewas separated from the upper phase, was washed with water, was treatedwith aqueous potassium hydroxide solution (53 g of 50%), and was thenrefluxed for one hour. A second azeotropic distillation and waterwashing yielded crude product which was further purified by distillationthrough a ten-plate perforated column to provide the product ether(boiling range 82-84° C.; 96.2% purity by GLC). The product identity wasconfirmed by GCMS and by ¹H and ¹⁹F NMR.

[0108] Preparation of C₅F₁₁OC₂H₅

[0109] The title compound was prepared essentially as in Example 3 usinganhydrous potassium fluoride (38.6 g, 0.67 mol), anhydrous diethyleneglycol dimethyl ether (diglyme, 500 g), methyltrialkyl(C₈-C₁₀)ammoniumchloride (Adogen™ 464, available from Aldrich Chemical Company, 10.5 g),C₄F₉COF (260 g of 60.7% purity, 0.59 mol), and diethyl sulfate (102.4 g,0.67 mol). The reaction mixture was stirred at room temperatureovernight, and then the resulting product was azeotropically distilledfrom the reaction mixture. The lower product phase of the resultingdistillate was separated from the upper phase and was treated withapproximately 50 g of 50% aqueous potassium hydroxide, was refluxed forfour hours, and was stirred at room temperature overnight. A secondazeotropic distillation and water washing gave crude product which wasfurther purified by distillation through a ten-plate perforated columnto provide the product ether (boiling point 96° C.; 99.6% purity by GLC)The product identity was confirmed by GCMS and by ¹H and ¹⁹F NMR.

[0110] Solvency Properties

[0111] A number of potential solvents were tested for their ability todissolve hydrocarbons of increasing molecular weight according to theprocedure described in U.S. Pat. No. 5,275,669 (Van Der Puy et al.), thedescription of which is incorporated herein by reference. The data shownin Table 1 were obtained by determining the largest normal hydrocarbonalkane which was soluble in a particular solvent at a level of 50percent by volume. The numbers in the Table correspond with the carbonnumber of the largest alkane, e.g., “8” refers to octane. Measurementswere made from room temperature up to the boiling point of the solvent.For comparative purposes, hydrofluorocarbons (HFCs) and perfluorocarbons(PFCs) were also tested using this method. TABLE 1 Temperature (° C.)C₄F₉OCH₃ C₄F₉OC₂H₅ c-C₆F₁₁OCH₃ CF₃CFHCFHC₂F₅ C₆F₁₄ C₈F₁₈ C₅F₁₁H C₆F₁₃H23 9 12 10 7 6 5 7 7 30 10 12 11 7 40 10 13 11 8 6 6 8 8 50 12 14 13 8 76 8 55 12 15 13 9 60 12 15 13 7 7 9 73 17 15 7 10 101 18 9 h(S)

[0112] The data in Table 1 show that hydrocarbon alkanes aresignificantly more soluble in the alkoxy-substituted perfluorocompoundsused in the cleaning process of this invention than in the comparativecompounds, the HFCs and PFCs. This improved solvency was more pronouncedat elevated temperatures. Thus, the cleaning process of the inventioncan be used to remove higher molecular weight hydrocarbons (e.g., oilsand greases) from substrate surfaces than can be removed using HFCs orPFCs. The higher solvency of the alkoxy-substituted perfluorocompoundsfor hydrocarbon alkanes indicates that these perfluorocompounds canserve not only as superior cleaning solvents for removing hydrocarbonsoils, but can also be effective as solvents for depositing hydrocarboncoatings, e.g., coatings of lubricant, onto substrate surfaces.

[0113] Using essentially the above-described method, the solvencyproperties of other alkoxy-substituted perfluorocompounds were tested atroom temperature. The compounds tested and the results obtained areshown in Table 2 below. TABLE 2 Compound Largest Soluble

9

11  C₈F₁₇OCH₃ 6 (CF₃)₂CFCF₂OCH₃ 9 C₂F₅CF(OCH₃)CF(CF₃)₂ 8CF₃CF(OCH₃)CF(CF₃)₂ 9 C₃F₇OCH₃ 10  C₅F₁₁OCH₃ 8 C₅F₁₁OC₂H₅ 10 

8

7

9

8

Examples 8-10 and Comparative Examples A-C

[0114] In the following Examples and Comparative Examples, the cleaningability of the alkoxy-substituted perfluorocompounds used in thecleaning process of the invention was further evaluated. A 1.28 cm×1.28cm×0.225 cm wire-wrapped, aluminum coupon was coated with white heavymineral oil (available from Aldrich Chemical) by immersing the coupon inan oil-filled beaker. The initial amount of the oil on the coupon wasdetermined by weighing it on an analytical balance to the nearest 0.1mg. The coupon was immersed in a container of solvent and sonicated for1 minute at the indicated temperature (see Table 3 below for thesolvents and temperatures used). The coupon was then weighed again, andthe results were recorded in Table 3 as percent-oil removal. TABLE 3Example 8 9 10 Comparative A Comparative B Comparative C Temp. C₄F₉OCH₃C₄F₉OC₂H₃ c-C₆F₁₁OCH₃ C₆F₁₄ C₆F₁₃H CF₂ClCFCl₂ ° C. 23 60.3 56.0 74.454.9 71.7 98.9 50 98.7 99.2 96.5 67.6 86.6 98.7 60 99.9 100.0 99.8

[0115] The data in Table 3 show that the alkoxy-substitutedperfluorocompounds removed amounts of the mineral oil which werecomparable to the amounts removed by the comparative PFC and HFCcompounds at room temperature. At elevated temperature, the cleaningproperties of the perfluorocompounds were superior to those of the PFCand HFC compounds and equivalent to those of the comparative CFCcompound.

Examples 11-13

[0116] Using essentially the same procedure as that described inExamples 8-10, the ability of the alkoxy-substituted perfluorocompoundsto remove a fluorinated oil was evaluated. As in the previous Examples,a coupon was immersed in Krytox™ 157FSM perfluoropolyether oil havingcarboxylic acid end groups (available from DuPont), and the percent oilremaining after immersion in the solvent (at room temperature) wasdetermined. The results are shown in Table 4 below. TABLE 4 Example 1112 13 Compound C₄F₉OCH₃ C₄F₉OC₂H₅ c-C₆F₁₁OCH₃ % Removed 99.1 99.3 96.5

[0117] The data show that the alkoxy-substituted perfluorocompounds veryeffectively removed the perfluoropolyether oil from the surface of thecoupon. This indicates that the perfluorocompounds can function well ascleaning solvents for the removal of halogenated compounds such ashalogenated oils and greases.

Examples 14-16 and Comparative Examples D-E

[0118] The ability of alkoxy-substituted perfluorocompounds to functionas a rinse agent in a co-solvent cleaning process was evaluated. Theabove-described aluminum coupon was coated with solder flux (availablefrom Alpha Metals as Alpha 611 rosin, mildly activated flux) byimmersing the coupon into a flux-filled beaker. The flux-coated couponwas then dried using a forced air convection drier. The initial amountof the flux on the coupon was determined by weighing it on an analyticalbalance to the nearest 0.1 mg. The coupon was immersed in a container ofa mixed solvating agent comprising approximately 50% methyl decanoateand 50% dipropylene glycol di-n-butyl ether and was sonicated for 1minute at approximately 55° C. The coupon was then immersed for 30seconds into alkoxy-substituted perfluorocompound which had been heatedto its boiling point. The coupon was weighed again, and the results wererecorded in Table 5 below as percent oil removed from the coupon. TABLE5 Comparative Comparative Example 14 15 16 D E Compound C₄F₉OCH₃C₄F₉OC₂H₅ c-C₆F₁₁OCE₃ C₆F₁₄ C₆F₁₃H % 100.0 100.0 100.0 51.9 91.2 Removed

[0119] The data in Table 5 show that the alkoxy-substitutedperfluorocompounds (used according to the cleaning process of theinvention) effectively removed the solvating agent and flux residues,showing solvency properties superior to those of the comparative PFC andHFC compounds.

Examples 17-18 and Comparative Example F

[0120] The above-described aluminum coupon was dipped into Brayco 815Zperfluoropolyether oil (available from Castrol Inc., molecular weight ofabout 10,000) and then immersed in alkoxy-substituted perfluorocompoundvapor (over the boiling liquid) for 60 seconds. The percent oil removalwas determined in the above-described manner. The results are shown inTable 6. TABLE 6 17 18 Comparative F Compound C₄F₉OCH₃ C₄F₉OC₂H₅ C₆F₁₄Percent Soil 89.9% 93.3% 92.9% Removed

Examples 19-20 and Comparative Example G

[0121] The above-described test coupon was dipped into a paraffinic oilcomprising a mixture of linear and branched hydrocarbons (DuoSeal PumpOil, available from Sargent Welch), was immersed in mixed solvatingagent comprising approximately 500% methyl caproate and 50% dipropyleneglycol di-n-butyl ether for 30 seconds, and was then rinsed in boilingalkoxy-substituted perfluorocompound for 30 seconds. The percent oilremoval was,determined in the above-described manner. The results areshown in Table 7. TABLE 7 19 20 Comparative G Compound C₄F₉OCH₃C₄F₉OC₂H₅ C₆F₁₄ Percent Soil 99.8% 100.0% 89.2% Removed

Examples 21-22

[0122] The above-described test coupon was dipped in white heavy mineraloil (available from Aldrich Chemical), was immersed in a boilingsingle-phase mixture of 40 volume % of a solvating agent comprisingessentially methyl decanoate and 60 volume % of alkoxy-substitutedperfluorocompound (a cleaning composition of the invention) for 60seconds, was cooled for 60 seconds, and was then immersed in mixturevapor for 30 seconds. The percent oil removal was determined in theabove-described manner. The results are shown in Table 8. TABLE 8 21 22Fluorinated Component C₄F₉OCH₃ C₄F₉OC₂H₅ of Cleaning Composition PercentSoil Removed 94.61% 94.28%

Examples 23-24 and Comparative Example H

[0123] The above-described test coupon was dipped into DuoSeal Pump Oil(available from Sargent-Welch), was immersed in a boiling mixture of 40volume % of a solvating agent comprising mixed terpenes having a boilingrange of 243-274° C. and 60 volume % of alkoxy-substitutedperfluorocompound (a cleaning composition of the invention), was cooledfor 60 seconds, and was then immersed in mixture vapor for 30 seconds.The percent oil removal was determined in the above-described manner.The results are shown in Table 9. TABLE 9 23 24 Comparative HFluorinated C₄F₉OCH₃ C₄F₉OC₂H₅ C₆F₁₄ Component of Cleaning CompositionPercent Soil 86.4% 99.4% 75.7% Removed

Examples 25-26 and Comparative Example I

[0124] The above-described test coupon was dipped into DuoSeal Pump Oil(available from Sargent-Welch) and was then immersed in a mixture of 40volume % n-C₆H₁₄ and 60 volume % alkoxy-substituted perfluorocompound (acleaning composition of the invention) for 60 seconds at roomtemperature with ultrasonic agitation. The percent oil removal wasdetermined in the above-described manner. The results are shown in Table10. TABLE 10 25 26 Comparative I Fluorinated C₄F₉OCH₃ C₄F₉OC₂H₅ C₆F₁₄Component of Cleaning Composition Percent Soil 92.5% 99.0% 88.5% Removed

Examples 27-28 and Comparative Example J

[0125] The above-described test coupon was dipped into DuoSeal Pump Oil(available from Sargent-Welch) and was then immersed in the vapor of aboiling mixture of 40 volume % n-C₆H₁₄ and 60 volume %alkoxy-substituted perfluorocompound (a cleaning composition of theinvention) for 60 seconds. The percent oil removal was determined in theabove-described manner. The results are shown in Table 11. TABLE 11Example 27 28 Comparative J Fluorinated C₄F₉OCH₃ C₄F₉OC₂H₅ C₆F₁₄Component of Cleaning Composition Percent Soil 90.8% 97.1% 73.8% Removed

[0126] The results obtained in Examples 17-28 show thatalkoxy-substituted perfluorocompounds are effective at removing avariety of contaminants from substrate surfaces.

[0127] In Examples 29 to 70 the process of cleaning textiles usingalkoxy-substituted perfluoroalkanes was demonstrated. The cleaningcompositions used were as follows:

[0128] Cleaning

[0129] Composition

[0130] A C₄F₉OCH₃ (neat)

[0131] B C₄F₉OC₂H₅ (neat)

[0132] C 0.5 wt. % C₄F₉OC₂F₄OCF₂C(O)NHC₂H₄OH, 0.2 wt. % Brij 30™ in C₄F₉OCH₃

[0133] D 0.5 wt. % C₄F₉OC₂F₄OCF₂C(O)NHC₂H₄OH, 0.2 wt. % Igepal CO-210™in C₄F₉CCH₃

[0134] E 0.5 wt. % FC-171™, 0.2 wt. % TRITON X-15™, in C₄F₉OCH₃

[0135] F 0.5 wt. % FC-171™, 0.2 wt. % TRITON X-15™, in C₄F₉OC₂H₅

[0136] BRIJ 30™ is an ethoxylated (poly)ethylene oxide available fromICI Chemical

[0137] IGEPAL CO-210™ is a nonylphenoxyethoxylate) is available fromRhone-Poulenc

[0138] TRITON X-15™ is an octylphenoxyethoxylate) is available fromUnion Carbide

[0139] FC-171™ is a fluorinated sulfonamide surfactant available from 3MCompany, St. Paul, Minn. C₄F₉OC₂F₄OCF₂C(O)NHC₂H₄OH may be prepared bythe method described in U.S. Pat. No. 5,125,978 (Flynn, et la.) and U.S.Pat. No. 15 5,089,152 (Flynn et al.)

[0140] In these Examples, fabric samples measuring about 15×15 cm andweighing about 10 grams were stained by adding three drops of mineraloil, and separately, three drops of corn oil, to the fabric, coveringthe stain with wax paper, and applying a 500 g weight for about oneminute to ensure oil penetration into the fabric. The samples were thenallowed to stand for about thirty minutes prior to each cleaning trial.

[0141] The stained fabrics were placed into individual quart glass jarswith 200 mL of a cleaning solution, capped, and then shaken for tenminutes. The cleaning solution was then drained and the fabric samplesrinsed with 200 mL of the same neat alkoxy-substituted perfluoroalkanefor five minutes, followed by air drying. The rinse step was omitted inExamples in which the neat fluorinated ether was used as the cleaningsolution.

[0142] The fabric samples were evaluated visually comparing the size andappearance of the stain on the untreated fabric to that of the cleanedfabric. The stains were then evaluated with a Model CR-300™ Chromometer(Minolta Camera, Japan) to quantify the color of the stain before andafter cleaning. Results are tabulated in the Tables below, organized bythe identity of the Oil and Fabric tested. In the tables, the value AErepresents the difference in color measurements between a stained and anunstained portion of the same fabric sample. In practice, a cleanedstain should have a Delta E value that is lower than an untreated(stained but not cleaned) sample. TABLE 12 Cleaning Example Solution OilFabric ΔE Visual Observation 29 Untreated Corn Oil 65/35 7.1 ± ControlPolyester 0.04 Cotton Twill 30 A ″ 65/35 4.52 ± Spot size decreased to2/3 Polyester 0.04 Cotton Twill 31 B ″ 65/35 4.58 ± Spot size decreasedto 2/3 Polyester 0.06 Cotton Twill 32 C ″ 65/35 4.56 ± Spot sizedecreased to 1/2 Polyester 0.00 Cotton Twill 33 D ″ 65/35 5.26 ± Spotsize decreased to 1/2 Polyester 0.04 Cotton Twill 34 E ″ 65/35 3.54 ±Spot size decreased to Polyester 0.12 less than 1/2 Cotton Twill 35 F ″65/35 4.56 ± Spot size decreased to Polyester 0.23 less than 1/4 CottonTwill

[0143] TABLE 13 Cleaning Example Solution Oil Fabric ΔE VisualObservation 36 Untreated Corn Oil 100% Cotton 0.27 ± Control style 4000.03 37 A ″ 100% Cotton 1.86 ± Spot size decreased style 400 0.30 to 1/238 B ″ 100% Cotton 2.6 ± Spot size decreased style 400 0.04 to 1/4 39 C″ 100% Cotton 0.39 ± Spot size decreased style 400 0.07 to less than 1/240 D ″ 100% Cotton 0.34 ± Spot size nearly style 400 0.06 gone 41 E ″100% Cotton 0.88 ± Spot size style 400 0.01 decreased to 1/2 42 F ″ 100%Cotton 0.76 ± Spot size decreased style 400 0.05 to 1/4

[0144] TABLE 14 Cleaning Visual Example Solution Oil Fabric ΔEObservation 43 Untreated Corn Oil 100% Wool 11.41 ± Control 0.75 44 A ″″ 10.46 ± No Change 0.13 45 B ″ ″ 8.87 ± No Change 0.07 46 C ″ ″ 8.96 ±No Change 0.16 47 D ″ ″ 9.78 ± No Change 0.08 48 E ″ ″ 8.74 ± No Change0.22 49 F ″ ″ 8.54 ± No Change 0.06

[0145] TABLE 15 Cleaning Visual Example Solution Oil Fabric ΔEObservation 50 Untreated Light 65/35 5.80 ± Control Mineral Polyester0.03 Oil Cotton Twill 51 A Light 65/35 0.50 ± Spot not visible MineralPolyester 0.07 Oil Cotton Twill 52 B Light 65/35 0.14 ± Spot not visibleMineral Polyester 0.16 Oil Cotton Twill 53 C Light 65/35 0.44 ± Spot notvisible Mineral Polyester 0.04 Oil Cotton Twill 54 D Light 65/35 0.36 ±Spot not visible Mineral Polyester 0.06 Oil Cotton Twill 55 E Light65/35 0.44 ± Spot not visible Mineral Polyester 0.19 Oil Cotton Twill 56F Light 65/35 0.20 ± Spot not visible Mineral Polyester 0.05 Oil CottonTwill

[0146] TABLE 16 Cleaning Visual Example Solution Oil Fabric ΔEObservation 57 Untreated Heavy 100% Cotton 0.40 ± Control Mineral Oilstyle 400 0.06 58 A Heavy 100% Cotton 0.37 ± Not visible Mineral Oilstyle 400 0.28 59 B Heavy 100% Cotton 0.13 ± Not visible Mineral Oilstyle 400 0.08 60 C Heavy 100% Cotton 0.22 ± Not visible Mineral Oilstyle 400 0.04 61 D Heavy 100% Cotton 0.17 ± Not visible Mineral Oilstyle 400 0.06 62 E Heavy 100% Cotton 0.15 ± Not visible Mineral Oilstyle 400 0.01 63 F Heavy 100% Cotton 1.20 ± Not visible Mineral Oilstyle 400 0.08

[0147] TABLE 17 Cleaning Example Solution Oil Fabric ΔE VisualObservation 64 Untreated Heavy Mineral 100% Wool 8.58 ± Control Oil 0.3365 A Heavy Mineral ″ 0.76 ± Faintly visible Oil 0.16 66 B Heavy Mineral″ 0.84 ± Faintly visible Oil 0.13 67 C Heavy Mineral ″ 0.67 ± Faintlyvisible Oil 0.10 68 D Heavy Mineral ″ 0.39 ± Not visible Oil 0.01 69 EHeavy Mineral ″ 0.57 ± Not visible Oil 0.21 70 F Heavy Mineral ″ 0.79 ±Not visible Oil 0.04

[0148] As can be seen in the above Tables, the mineral oil stains wereessentially completely removed with all cleaning solutions, based onboth visual and calorimetric analysis. The corn oil stains remained tosome degree on all fabrics. The polyester/cotton samples showed adecrease in stain size (diameter) and a lighter (less color) stain thanwith the untreated control, but addition of a surfactant to thealkoxy-substituted perfluoroalkane was more effective in reducing thesize and color of the stain. On the 1000% cotton samples, the neatalkoxy-substituted perfluoroalkane reduced the size of the stain, butmade the stain darker by the calorimetric measurements.

[0149] Various modifications and alterations of this invention will beapparent to those skilled in the art without departing from the scopeand spirit of this invention.

We claim:
 1. A dry cleaning process for removing contaminants from thesurface of a fabric substrate, the process comprising the step ofcontacting a fabric substrate with a liquid- and/or vapor-phase cleaningcomposition comprising at least one mono-, di-, or trialkoxy-substitutedperfluoroalkane, perfluorocycloalkane, perfluorocycloalkyl-containingperfluoroalkane, or perfluorocycloalkylene-containing perfluoroalkanecompound, said compound optionally containing one or more additionalcatenary heteroatoms.
 2. The process of claim 1 wherein said compoundhas a boiling point in the range of from about 25° C. to about 200° C.3. The process of claim 1 wherein said compound is represented by thegeneral formula R_(f)—(O—R_(h))_(x), wherein x is an integer of 1 to 3;when x is 1, R_(f) is selected from the group consisting of linear orbranched perfluoroalkyl groups having from 2 to about 15 carbon atoms,perfluorocycloalkyl-containing perfluoroalkyl groups having from 5 toabout 15 carbon atoms, and perfluorocycloalkyl groups having from 3 toabout 12 carbon atoms; when x is 2, R_(f) is selected from the groupconsisting of linear or branched perfluoroalkanediyl groups orperfluoroalkylidene groups having from 2 to about 15 carbon atoms,perfluorocycloalkyl- or perfluorocycloalkylene-containingperfluoroalkanediyl or perfluoroalkylidene groups having from 6 to about15 carbon atoms, and perfluorocycloalkanediyl groups orperfluorocycloalkylidene groups having from 3 to about 12 carbon atoms;when x is 3, R_(f) is selected from the group consisting of linear orbranched perfluoroalkanetriyl groups having from 2 to about 15 carbonatoms, perfluorocycloalkyl- or perfluorocycloalkylene-containingperfluoroalkanetriyl groups having from 6 to about 15 carbon atoms, andperfluorocycloalkanetriyl groups having from 3 to about 12 carbon atoms;each R_(h) is independently selected from the group consisting of linearor branched alkyl groups having from 1 to about 8 carbon atoms,cycloalkyl-containing alkyl groups having from 4 to about 8 carbonatoms, and cycloalkyl groups having from 3 to about 8 carbon atoms;wherein either or both of the groups R_(f) and R_(h) can contain one ormore catenary heteroatoms; and wherein the sum of the number of carbonatoms in R_(f) and the number of carbon atoms in R_(h) is greater thanor equal to
 4. 4. The process of claim 3 wherein x is 1; R_(h) is analkyl group having from 1 to about 6 carbon atoms; and R_(f) but notR_(h) can contain one or more catenary heteroatoms.
 5. The process ofclaim 4 wherein R_(f) is selected from the group consisting of linear orbranched perfluoroalkyl groups having from 3 to about 6 carbon atoms,perfluorocycloalkyl-containing perfluoroalkyl groups having from 5 toabout 8 carbon atoms, and perfluorocycloalkyl groups having from 5 toabout 6 carbon atoms; and R_(h) is an alkyl group having from 1 to about3 carbon atoms.
 6. The process of claim 1, wherein the cleaningcomposition further comprises surfactant.
 7. The process of claim 6,wherein the surfactant comprises a nonionic surfactant chosen from thegroup consisting of an ethoxylated alcohol, an ethoxylated alkylphenol,an ethoxylated fatty acid, an alkylaryl sulfonate, a glycerol ester, anethoxylated fluoroalcohol, a fluorinated sulfonamide, and mixturesthereof.
 8. The process of claim 6, wherein the cleaning compositioncomprises from about 0.1 to about 5 percent by weight surfactant.
 9. Adry cleaning process for removing contaminants from the surface of afabric substrate, the process comprising the step of contacting a fabricsubstrate with a liquid- and/or vapor-phase cleaning compositioncomprising at least one compound selected from the group consisting ofc-C₆F₁₁CF₂OC₂H₅, c-C₆F₁₁CF₂OCH₃, 4-CF₃-c-C₆F₁₀CF₂OCH₃,

CH₃OCF₂-c-C₆F₁₀CF₂OCH₃, C₄F₉OC₂H₅, C₄F₉OCH₃, c-C₆F₁₁OCH₃,(CF₃)₂CFCF₂OCH₃, (CF₃)₂CFCF₂OC₂H₅, C₈F₁₇OCH₃, C₂F₅CF(OCH₃)CF(CF₃)₂,CF₃CF(OCH₃)CF(CF₃)₂, C₅F₁₁OCH₃, C₅F₁₁OC₂H₅, and C₃F₇OCH₃.
 10. Theprocess of claim 9, wherein the cleaning composition further comprisessurfactant.
 11. The process of claim 10, wherein the surfactantcomprises a nonionic surfactant chosen from the group consisting of anethoxylated alcohol, an ethoxylated alkylphenol, an ethoxylated fattyacid, an alkylaryl sulfonate, a glycerol ester, an ethoxylatedfluoroalcohol, a fluorinated sulfonamide, and mixtures thereof.
 12. Theprocess of claim 10, wherein the cleaning composition comprises fromabout 0.1 to about 5 percent by weight surfactant.
 13. A cleaningcomposition comprising (a) a major amount of at least one mono-, di-, ortrialkoxy-substituted perfluoroalkane, perfluorocycloalkane,perfluorocycloalkyl-containing perfluoroalkane, orperfluorocycloalkylene-containing perfluoroalkane compound, saidcompound optionally containing one or more additional catenaryheteroatoms; and (b) surfactant.
 14. The composition of claim 13,wherein said compound has a boiling point in the range of from about 25°C. to about 200° C.
 15. The composition of claim 13, wherein saidcompound is represented by the general formula R_(f)—(O—R_(h))_(x),wherein x is an integer of 1 to 3; when x is 1, R_(f) is selected fromthe group consisting of linear or branched perfluoroalkyl groups havingfrom 2 to about 15 carbon atoms, perfluorocycloalkyl-containingperfluoroalkyl groups having from 5 to about 15 carbon atoms, andperfluorocycloalkyl groups having from 3 to about 12 carbon atoms; whenx is 2, R_(f) is selected from the group consisting of linear orbranched perfluoroalkanediyl groups or perfluoroalkylidene groups havingfrom 2 to about 15 carbon atoms, perfluorocycloalkyl- orperfluorocycloalkylene-containing perfluoroalkanediyl orperfluoroalkylidene groups having from 6 to about 15 carbon atoms, andperfluorocycloalkanediyl groups or perfluorocycloalkylidene groupshaving from 3 to about 12 carbon atoms; when x is 3, R_(f) is selectedfrom the group consisting of linear or branched perfluoroalkanetriylgroups having from 2 to about 15 carbon atoms, perfluorocycloalkyl- orperfluorocycloalkylene-containing perfluoroalkanetriyl groups havingfrom 6 to about 15 carbon atoms, and perfluorocycloalkanetriyl groupshaving from 3 to about 12 carbon atoms; each R_(h) is independentlyselected from the group consisting of linear or branched alkyl groupshaving from 1 to about 8 carbon atoms, cycloalkyl-containing alkylgroups having from 4 to about 8 carbon atoms, and cycloalkyl groupshaving from 3 to about 8 carbon atoms; wherein either or both of thegroups R_(f) and R_(h) can contain one or more catenary heteroatoms; andwherein the sum of the number of carbon atoms in R_(f) and the number ofcarbon atoms in R_(h) is greater than or equal to
 4. 16. The compositionof claim 13, wherein the surfactant comprises a nonionic surfactant. 17.The composition of claim 16, wherein the nonionic surfactant is selectedfrom the group consisting of an ethoxylated alcohol, an ethoxylatedalkylphenol, an ethoxylated fatty acids, an alkylaryl sulfonate, aglycerol ester, an ethoxylated fluoroalcohol, a fluorinated sulfonamide,and mixtures thereof.
 18. The composition of claim 13, wherein thecomposition comprises from about 0.1 to about 5 percent by weightsurfactant.
 19. A composition comprising (a) a major amount of at leastone compound selected from the group consisting of c-C₆F₁₁CF₂OC₂H₅,c-C6F₁₁CF₂OCH₃, 4 -CF₃ -c-C₆F₁₀CF₂OCH₃,

CH₃OCF₂-c-C₆F₁₀CF₂OCH₃, C₄F₉OC₂H₅, C₄F₉OCH₃, c-C₆F₁₁OCH₃,(CF₃)₂CFCF₂OCH₃, (CF₃)₂CFCF₂OC₂H₅, C₈F₁₇OCH₃, C₂F₅CF(OCH₃)CF(CF₃)₂,CF₃CF(OCH₃)CF(CF₃)₂, C₅F₁₁OCH₃, C₅F₁₁OC₂H₅, and C₃F₇OCH₃; and (b)surfactant.
 20. The composition of claim 19, wherein the surfactantcomprises a nonionic surfactant.
 21. The composition of claim 20,wherein the nonionic surfactant is selected from the group consisting ofan ethoxylated alcohol, an ethoxylated alkylphenol, an ethoxylated fattyacids, an alkylaryl sulfonate, a glycerol ester, an ethoxylatedfluoroalcohol, a fluorinated sulfonamide, and mixtures thereof.
 22. Thecomposition of claim 19, wherein the composition comprises from about0.1 to about 5 percent by weight surfactant.
 23. A process for removingcontaminants from a substrate comprising the steps of contacting asubstrate with a liquid- and/or vapor-phase cleaning compositioncomprising (a) at least one mono-, di-, or trialkyloxy-substitutedperfluoroalkane, perfluorocycloalkane, perfluorocycloalkyl-containingperfluoroalkane, or perfluorocycloalkylene-containing perfluoroalkanecompound, said compound optionally containing one or more additionalcatenary heteroatoms; and (b) surfactant.